Treatment of tumour necrosis factor-alpha (TNF-α)-related autoimmune diseases, such as rheumatoid arthritis, psoriasis and other autoimmune diseases, has been achieved through the use of FDA-approved drugs such as Adalimumab (HUMIRA®, Abbott Corporation). Adalimumab is a human monoclonal antibody that inhibits human TNF-α activity so as to prevent it from activating TNF receptors, thereby downregulating inflammatory responses associated with autoimmune diseases. Approved medical indications for Adalimumab include rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, ulcerative colitis, moderate to severe chronic psoriasis and juvenile idiopathic arthritis.
Adalimumab is generally delivered to a patient via subcutaneous injection, and is thus provided in a liquid form, typically in packages such as vials, preloaded syringes, or preloaded “pen devices”. Commercially available pen devices (HUMIRA® Pen) generally include a 1 mL pre-filled glass syringe, preloaded with 0.8 mL of a sterile formulation of 40 mg Adalimumab (see below), with a fixed needle (either gray natural rubber or a latex free version) and a needle cover. Commercial formulations (HUMIRA®) of Adalimumab contain the following ingredients:
Amount per container (mg)Ingredient(filling volume = 0.8 mL)Amount (mg/mL)Adalimumab4050Citric Acid1.041.3MonohydrateDibasicsodium1.221.53phosphatedihydrateMannitol9.612Monobasicsodium0.690.86phosphatedihydratePolysorbate 800.81Sodium chloride4.936.16Sodium citrate0.240.3WFI and sodiumq.b. to adjust pH to 5.2q.b. to adjust pH to 5.2hydroxide
Adalimumab, and its method of manufacture, is described in WO97/29131 (BASF) as D2E7, and elsewhere in the art.
Though the aforementioned commercial formulation of Adalimumab is stable (at least to some extent), the relevant antibody may be unstable over prolonged periods or under stressed conditions, thus precluding prolonged storage of said formulations. Such degradation of the formulation may be due to a variety of factors, including:                Physical effects, such as:                    Inadequate inhibition of aggregation of the relevant protein molecules (a function supposedly served by Tween®80 (polysorbate 80));            Inadequate inhibition of precipitation;            Inadequate inhibition of adsorption of the relevant protein molecules at the interface of water and air or at the contact surface of any packaging material (a function supposedly served by Tween®80 (polysorbate 80));            Inadequate regulation of osmotic pressure (a function supposedly served by mannitol);                        Chemical effects, such as:                    Inadequate regulation of oxidation (a function supposedly served by mannitol and potentially undermined by Tween®80 (polysorbate 80), which can promoted oxidation of double bonds);            Inadequate inhibition of photo-oxidation;            Inadequate inhibition of hydrolysis of ester bonds leading to the formation of acid, aldehyde and peroxide products, thus affecting the stability of the antibody;            Inadequate stabilisation and maintenance of pH;            Inadequate inhibition of protein fragmentation;            Inadequate inhibition of protein unfolding;                        
Any, some, or all of the above factors can lead to either an unviable drug product (which may be unsafe for use in medical treatments) or a drug product whose viability is variable and unpredictable, especially in view of the variable stresses (agitation, heat, light) different batches of drug product may be exposed to during manufacture, transport, and storage.
In terms of the physical and chemical stabilisation of Adalimumab, the complex array of components within the aforementioned commercial formulations appears to perform below expectations, especially in view of the large number of components. Though this particular combination of excipients undoubtably represents a ‘delicate balance’ (given the interplay between various technical factors) and was the result of extensive research and development, in view of the risk of underperformance it is questionable whether such a large number of different excipients is justified, especially given that this inevitably increases processing and cost burdens, toxicity risks, and risks of deleterious interactions between components that could compromise the formulation. Even if the overall performance of the commercial formulations could not be surpassed, an alternative formulation having comparative performance but containing few components would represent a highly desirable replacement for the commercial formulations, for at least the aforesaid reasons.
In order to guarantee reproducible clinical performance of a protein-based pharmaceutical product, such products must remain in a stable and consistent form over time. It is well-established that molecular alterations can occur during every stage of the manufacturing process, including during the production of the final formulation and during storage. Molecular alterations can modify a quality attribute of a biopharmaceutical product, resulting in an undesirable change in the identity, strength or purity of the product. Some such problems are outlined above.
The primary goal of formulation development is to provide a pharmaceutical composition that will support the stability of a biopharmaceutical protein during all stages of its production, storage, shipping and use. Formulation development for an innovative biopharmaceutical protein, or a biosimilar monoclonal antibody (mAb), is essential to its safety, clinical efficacy and commercial success.
There is therefore a need for the provision of alternative or improved liquid formulations of adalimumab. Desirably, any new formulations would solve at least one of the aforementioned problems and/or at least one problem inherent in the prior art, and may suitably solve two or more of said problems. Desirably, the problem(s) of the prior art may be solved whilst reducing the complexity of the formulation.